1. Field
The present disclosure relates to a method of manufacturing an organic light emitting display apparatus.
2. Description of the Related Technology
Among display devices, an organic light emitting display apparatus has attracted much attention as an advanced display device because it has a wide viewing angle, a high contrast ratio, and a high response speed.
A typical organic light emitting display apparatus has a stack structure in which an emission layer (EML) is inserted between an anode and a cathode so that holes and electrons injected from the anode and the cathode recombine in the EML to emit light. In some such apparatuses, an additional layer, such as an electron injection layer (EIL), an electron transport layer (ETL), a hole transport layer (HTL), and a hole injection layer (HIL), may be selectively inserted between each of the anode and the cathode and the EML.
The EML and the additional layer disposed between the anode and the cathode may be formed using various methods, such as a vacuum evaporation method or a laser-induced thermal imaging (LITI) method. Recently, an inkjet printing method has been used to form the EML and the additional layer.
In general, the inkjet printing method may be a non-contact patterning technique of spraying a solution or a suspension as the type of droplets with a size of one to several tens of pico liter (pl) through fine nozzles. In the inkjet printing method, patterns may be freely printed at a resolution of several micrometers (mm). The inkjet printing method is currently being applied to a process of forming color filters and electrodes in the display fields of, such as plasma display panels (PDPs), liquid crystal displays (LCDs), and organic light emitting displays (OLEDs). Furthermore, the inkjet printing method is also being applied to flexible electronic devices and semiconductor circuits including electronic papers (E-papers) or radio-frequency identification (RFID).